#include <iostream>
#include <algorithm>
#include <cstring>
#include <string>
using namespace std;
int a[1002][1002];
//默认长度为1
int len = 1;
void fun(int);
int main()
{
    int m, n;
    cin >> m >> n;
    a[1][0] = 1;
    a[2][0] = 2;
    for (int i = 3; i <= n - m; i++)
    {
        fun(i);
    }
    for (int i = len - 1; i >= 0; i--)
    {
        cout << a[n - m][i];
    }
    cout << endl;
    return 0;
}
void fun(int temp)
{
    for (int i = 0; i <= len - 1; i++)
    {
        a[temp][i] += a[temp - 1][i] + a[temp - 2][i];
        if (a[temp][i] >= 10)
        {
            a[temp][i + 1] += a[temp][i] / 10;
            a[temp][i] %= 10;
        }
        //进位
        if (a[temp][len])
        {
            len++;
        }
    }
}
